FST.RegTypes

Functions for constructing a simplified regular expression.

Type classes

class Combinators a where

Combinators. The regular expressions are simplified while combined.

Methods

(<|>)

Arguments

:: a

-> a

-> a

Union

(|>)

Arguments

:: a

-> a

-> a

Concatenation

star

Arguments

:: a

-> a

Kleene's star

plus

Arguments

:: a

-> a

Kleene's plus

empty

Arguments

:: a

Empty language

Instances

Eq a => Combinators (Reg a)

Eq a => Combinators (RReg a)

class Symbols f where

Type class for the collection of symbols in an expression.

Methods

symbols

Arguments

:: Eq a

=> f a

-> [a]

Collect the symbols in a regular expression.

Instances

Symbols Reg

Symbols RReg

Types

data Reg a

Data type for a regular expression.

Constructors

Empty

Epsilon

0

All

?

Symbol a

a

(Reg a) :|: (Reg a)

r1 | r2

(Reg a) :.: (Reg a)

r1 r2

(Reg a) :&: (Reg a)

r1 & r2

Complement (Reg a)

~[ r1 ]

Star (Reg a)

r2

*

Instances

Symbols Reg

Eq a => Eq (Reg a)

Show a => Show (Reg a)

Eq a => Combinators (Reg a)

Combinators

(<&>) :: Eq a => Reg a -> Reg a -> Reg a

Intersection

(<->) :: Eq a => Reg a -> Reg a -> Reg a

Minus. Definition A - B = A & ~B

complement :: Eq a => Reg a -> Reg a

Complement

reversal :: Eq a => Reg a -> Reg a

Reverse the language denoted by the regular expression.

allFree :: Eq a => Reg a -> [a] -> Reg a

Construct a ?-free regular expression with respect to an alphabet [a]

Constructors

s :: a -> Reg a

Symbol

eps :: Reg a

Epsilon

allS :: Reg a

All symbol

allToSymbols :: Eq a => [a] -> Reg a

Transform the all symbol to union over alphabet. ? -> [a|..] with respect to an alphabet [a]

Query functions

acceptEps :: Eq a => Reg a -> Bool

Examines if a regular expression accepts the empty string.